11.  ADVANCED MATERIALS AND TECHNOLOGIES FOR COOLING AND WASTE HEAT RECOVERY

 

Refrigeration, air conditioning, and other cooling requirements in the buildings, industry, and transportation sectors account for about 10 quads of U.S. primary energy consumption.  Most conventional air conditioners, heat pumps, and refrigerators achieve cooling through a mechanical vapor compression cycle (VCC).  The efficiency of the best VCC systems may be approaching asymptotic values; hence, the potential for significant improvement of current technologies may be limited.  Further, air conditioning is a major contributor to electric utility peak loads (which incur high generation costs and use equipment with low efficiencies).  Similarly, in the transport sector, air conditioning is a large load that constrains the design of hybrid vehicles; overall, A/C accounts for roughly one-fifth of the power required by a mid-sized sedan traveling at 60 mph on a hot day.  These factors encourage the search for new approaches to increase the energy efficiency of cooling technologies.   

 

Another problem concerns the adverse environmental impact of the refrigerant gas used in the mechanical VCCs of conventional air conditioners and refrigerators.  Although the refrigerant gases used today are considered safe for the ozone layer (per the Montreal Protocol), they are strong greenhouse gases.  For example, on a per-molecule basis, the refrigerant R-134a used in vehicles has 1300 times the direct Global Warming Potential of carbon dioxide over a 100-year period.  Current vehicular air conditioners leak 10 to 70 grams of R-134a per year.  The European Union (EU) bans the use of R-134a in new model cars introduced in 2011 (and in all cars by 2017).  There are also large refrigerant losses from residential and commercial air conditioners and refrigerators. 

 

The Department of Energy is seeking the development of advanced technologies for space cooling in buildings and vehicles – as well as for refrigeration in residential, commercial, and industrial applications – that are more energy efficient, that avoid net direct greenhouse gas emissions, that reduce lifecycle costs, and that can impact large markets.  Technologies of interest include solid-state materials and devices, advanced working fluids and mechanical vapor compression systems, and advanced contributory technologies such as heat exchangers and heat transfer fluids.

 

In addition, the Department of Energy is seeking the development of advanced technologies to capture some of the waste thermal energy from processes in the buildings, transportation, and industrial sectors for use in cooling applications or in generating electricity.  Many processes within these sectors discharge large quantities of lower-grade thermal energy.  Technologies of interest include solid-state materials and devices, and advanced absorption cycles – including those that use solar thermal energy.

 

Grant applications submitted in response to this topic must:  (1) include a review of the state-of-the-art of the technology and application being targeted; (2) provide a detailed evaluation of the proposed technology and place it in the context of the current state-of-the-art; (3) analyze the proposed technology development process, the pathway to commercialization, and the attendant potential public benefits that would accrue; (4) address the ease of implementation of the new technology, its ability to be installed with commonly-available skill sets, and its potential for high reliability; (5) demonstrate that the proposed technology has the potential to be more energy efficient and have reduced lifecycle costs compared to current technologies; (6) have high reliability; and (7) address a large potential market.

 

Phase I must include (1) a preliminary design, (2) a characterization of laboratory devices using the best measurements available, including a description of the measurement methods, and (3) the preparation of a road map with major milestones, leading to a production model of a system for consideration in Phase II.  In Phase II, devices suitable for near-commercial applications must be built and tested, and issues associated with manufacturing the units in large volumes at a competitive price must be addressed. 

 

Grant applications are sought only in the following subtopics:

 

a. Solid-State Materials and Devices for Refrigeration and Air-Conditioning Applications—Solid state devices offer the potential to provide higher energy efficiencies than current VCC technologies, to eliminate the use of refrigerants and their greenhouse gas impacts, and to provide highly-durable long-life units.  Today, however, solid-state devices such as thermoelectrics have significantly lower efficiencies than conventional VCC technologies.  Therefore, grant applications are sought to develop solid state materials and technologies that have the potential to provide improved cost and performance compared to conventional VCC technologies.  Grant applications must address (1) solid-state materials and devices such as thermoelectrics, magnetocalorics, electrocalorics, and thermotunneling or (2) other solid state systems. 

 

Questions – contact Sam Baldwin (Sam.Baldwin@ee.doe.gov)

 

b. Advanced Working Fluids and Mechanical Vapor Compression Systems—Current VCC technologies have a well-established technology, manufacturing, marketing, and support infrastructure around the world.  But current VCC technologies appear to have a relatively limited potential for significant further improvements in energy efficiency.  Further, current VCC working fluids are strong greenhouse gases.  Therefore, grant applications are sought to develop novel working fluids and mechanical VCC systems that have the potential to provide improved energy efficiency and lifecycle cost compared to conventional VCC technologies, with no net greenhouse gas impact due to the working fluid. 

 

Questions – contact Sam Baldwin (Sam.Baldwin@ee.doe.gov)

 

c. Advanced Heat Exchanger Technologies—Heat exchangers serve as the interface between the cooling technology and the outside environment.  Heat exchanger efficiencies and high capital costs remain key constraints in overall cooling system cost and performance.  Grant applications are sought to develop heat exchanger technologies with significantly higher performance and lower cost.  Approaches of interest include improved materials of construction, improved heat transfer fluid materials (including nanostructured fluids), and improved heat exchanger design.    

 

Questions – contact Sam Baldwin (Sam.Baldwin@ee.doe.gov)

 

 

d. Advanced Waste Heat Recovery for Electricity Generation or Cooling Applications—The buildings, transportation, and industrial sectors discharge large quantities of thermal energy from their processes.  For example, over half of the energy in gasoline is discharged from a vehicle as waste heat.  Systems such as bottoming cycle turbines have long been used for large scale (into the multi-megawatt range) capture of waste heat to produce electricity.  At small scales, thermoelectrics have been used in special cases, but their high cost and low efficiency have limited their widespread application.  Grant applications are sought to develop (1) solid state materials and devices, such as thermoelectrics or others that can capture waste heat for the production of electricity; and (2) advanced absorption cycles that can use waste heat or solar thermal energy to provide direct cooling for building applications.  Approaches of interest must demonstrate that the proposed technology will provide much higher efficiency and lower costs than systems available today.

 

Questions – contact Sam Baldwin (Sam.Baldwin@ee.doe.gov)

 

References:

 

Subtopics a & d: Solid-state materials and devices such as thermoelectrics, magnetocalorics, electrocalorics, and thermotunneling or other solid state systems;

 

Thermoelectrics:

 

1        G. Jeffrey Snyder and Eric S. Toberer, “Complex Thermoelectric Materials”, Nature Materials, V.7, Februaru 2008, pp.105-114.

 

2        Joseph P. Heremans, et al., “Enhancement of Thermoelectric Efficiency in PbTe by Distortion of the Electronic Density of States”, Science V.321, 25 July 2008, pp554-557

 

3        Fairbanks, J, "Thermoelectric Generators for Near-Term Automotive Applications and Beyond", Plenary  Presentation , European Thermoelectric Conference '06, Cardiff, Wales, April 10-11, 2006  (Full Text available at:  http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2006/session6/2006_deer_fairbanks.pdf)

 

4        Bell, Lon, "Role of Thermoelectrics in Vehicle Efficiency Increases", 11th Diesel Engine Emissions Reduction Conference, Chicago, Illinois, August 21-25, 2005 (Full text available at:  http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2005/session6/2005_deer_bell.pdf)

 

5        Robert F., “Semiconductor Advance May Help Reclaim Energy From ‘Lost’ Heat”, Science, 31 March 2006, V.311, p.1860 (Full text available at:  http://www.sciencemag.org/cgi/content/summary/311/5769/1860a)

 

6        Jianlin Liu, “Thermoelectric Coolers and Power Generators Using Self-assembled Ge Quantum Dot Superlattices”, University of California Energy Institute, September 2004 (Full text available at: http://repositories.cdlib.org/ucei/basic/FSE005/)

 

7        M. S. Dresselhaus, et. al., “Investigation of Low-Dimensional Thermoelectrics”, (Full text is available at:  http://www-rcf.usc.edu/~scronin/pubs/d888.pdf)

 

MagnetoCalorics:

 

1        K.A. Gschneider, Jr., V.K. Pecharsky, and A.O. Tsokol, “Recent developments in MagnetoCaloric Materials,” Rep. Prog. Phys, V.68 (2005) 1479-1539 (Full text available at: http://www.iop.org/EJ/abstract/0034-4885/68/6/R04/)

 

2        C. Zimm, et al., “Description and Performance of a Near-Room Temperature Magnetic Refrigerator,” Advances in Cryogenic Engineering, Editor: P. Kittel, Plenum Press, New York, 1998. (ISBN 0-3064-58071)

 

3        Zhengrong Xia, Yue Zhang, Jincan Chen, Guoxing Lin, “Performance Analysis and Parametric Optimal Criteria of an Irreversible Magnetic Brayton-Refrigerator”, Applied Energy V.85, @008, pp.159-170.

 

ElectroCalorics:

 

1        A.S. Mischenko, et al., “Giant Electrocaloric Effect in Thin-Film PbZr0.95Ti 0.05O3,”  Science, 3 March 2006, V.311, p.1270-1271. (Full text available at: http://www.sciencemag.org/cgi/reprint/311/5765/1270.pdf)

 

2        Bret Neese, et al., “Large Electrocaloric Effect in Ferroelectric Polymers Near Room Temperature”, Science, V.321, 8 August 2008, pp.821-823

 

ThermoTunneling:

 

1        M. Savin, et al., “Efficient electronic Cooling in Heavily Doped Silicon by Quasi particle Tunneling”, Applied Physics Letters, Vol.79, N.10, pp.1471-1473. (Full text available at: http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=APPLAB000079000010001471000001&idtype=cvips&prog=normal)

 

2        Yoshikazu Hishinuma, et al., “Measurements of cooling by room-temperature thermionic emission across a nanometer gap”, Journal of Applied Physics, V.94, N.7, 1 October 2003, pp.4690-4696 (Full text available at: http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=JAPIAU000094000007004690000001&idtype=cvips&prog=normal)

 

Subtopic b:

 

1        Ki-Jung Park, Taebeom Seo, Dongsoo Jung, “Performance of Alternative Refrigerants for Residential Air-Conditioning Applications”, Applied Energy 84 (2007) 985-991.

 

2        Steve Fischer and Solomon Labinov, “Not-In-Kind Technologies for Residential and Commercial Unitary Equipment”, Oak Ridge National Laboratory, February 2000.

 

Subtopic c:  

 

1        A.K. Gholap and J.A. Khan, “Design and Multi-Objective Optimization of Heat Exchangers for Refrigerators”, Applied Energy V.84 (2007), pp.1226-1239

 

2        Pawel Keblinski, Ravi Prasher, Jacob Eapen, “Thermal Conductance of Nanofluids: Is the controversy Over?”, J. Nanopart Res. DOI 10.1007/s11051-007-9352-1

 

3        Warren M. Rohsenow, James P. Hartnett, Young I. Cho, “Handbook of Heat Transfer”, Third Edition, McGraw Hill, New York, NY, 1998

 

Subtopic d:  See also Subtopic a.

 

1        Pongsid Srikhirin, Satha Aphornratana, Supachart Chungpaibulpatana, “A Review of absorption refrigeration technologies”. Renewable and Sustainable Energy Reviews V.5, 2001, pp.343-372.

 

2        A. Yokozeki and Mark B. Shiflett, “Vapor-Liquid Equilibria of Ammonia+Ionic Liquid Mistures”, Applied Energy V.84, 2007, pp.1258-1273

 

3        A. O. Dieng, R.Z. Weng, “Literature Review on Solar Adsorption Technologies for Ice-Making and Air-Conditioning Purposes and Recent Developments in Solar Technology”, Renewable and Sustainable Energy Reviews V.5, (2001), pp.313-342

 

4        Xiaohong Liao, Patricia Garland, Reinhard Radermacher, “The Modeling of Air-Cooled Absorption Chiller Integration in CHP Systems”, 2004 ASME International Mechanical Engineering Congress and Exposition, November 13-20, 2004, Anaheim, California